Low Cost
Triple CRT Driver
CVA3404T
FEATURES
Rise/Fall Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0ns
Swing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65V
P-P
Emitter Peaking Option
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90V
Excellent Gray Scale Linearity
Consistent EMI Performance
APPLICATIONS
CRT driver for up to 69kHz monitors with resolution up
to 1280 x 1024.
Excellent Gray Scale Linearity
DESCRIPTION
The CVA3404T contains three high impedance wideband
amplifiers, designed specifically to drive a CRT. It features no
crossover distortion for excellent gray scale linearity. This device
can drive monitors with resolutions of 1280 x 1024
(non-interlaced) with pixel frequency of 160MHz.
The part is housed in the industry standard 11-lead TO-220
molded power package. The heat sink is grounded.
ORDERING INFORMATION
Part
Package
Temperature
CVA3404T
T11A
-20
o
C to +100
o
C
CORPORATION
CONNECTION DIAGRAM AND SIMPLIFIED SCHEMATIC
OUT
OUT
11
10
9
8
7
6
5
4
3
2
1
IN
TOP VIEW
T11A PACKAGE
V
V
V
V
BIAS
V
CC
1P-22
OUT
V
IN
V
IN
V
GND = TAB
1
2
3
3
2
1
EMITTER
PEAKING
1
EMITTER
PEAKING
3
EMITTER
PEAKING
2
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
1P-23
9
V
CC
1,3,5
V
BIAS
V
OUT
11,9,8
V
IN
R
1
R
4
R
5
R
2
10
R
3
R
6
R
1
TAB = GND
EMITTER
PEAKING
2,4,7
ABSOLUTE MAXIMUM RATINGS
Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90V
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14W
Storage Temperature . . . . . . . . . . . . . . . . . . . -50
o
C to +150
o
C
ESD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000V
Operating Temperature . . . . . . . . . . . . . . . . . -20
o
C to +100
o
C
Lead Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300
o
C
CVA3404T
CORPORATION
FIGURE 1. TEST CIRCUIT
GND
TAB
1P-30
V
IN
V
BIAS
C1 = 0.01
F
C2 = 100
F
C3 = 0.1
F
D1, D2 = FHD400
C4 = 100
F
C5 = 27pF
C6 = 8pF
C6
C4
C3
C2
C1
D2
D1
VIDEO
INPUT
V
CC
11,9,8
10
1,3,5
V
OUT
TEKTRONIX
FET PROBE
MODEL 6201
(CAP. 1.5pF)
CVA3404T
6
R1 = 47
2,4,7
R1
C5
DC ELECTRICAL CHARACTERISTICS V
s
= 80V, C
L
= 8pF, DC
INPUT BIAS
= 12V, V
IN
= 2.2V, V
OUT
= 50V
p-p
. T
CASE
= +25
o
C.
See Figure 1.
SYMBOL
CHARACTERISTICS
MIN
TYP
MAX
UNITS
I
cc
Supply Current, Per Channel
20
26
mA
I
B
Bias Current
40
mA
V
OUT DC
Output DC Level
47
50
53
V
A
v
Voltage Gain
-11
-13
-15
V
Gain Matching
0.5
dB
AC ELECTRICAL CHARACTERISTICS V
s
= 80V, C
L
= 8pF, DC
INPUT BIAS
= 12V, V
IN
= 2.2V, V
OUT
= 40V
p-p
. T
CASE
= +25
o
C.
See Figure 1.
SYMBOL
CHARACTERISTICS
MIN
TYP
MAX
UNITS
T
r
Rise Time
6
ns
T
f
Fall Time
6
ns
L
e
Linearity
5
%
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
CVA3404T
CORPORATION
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
APPLICATION INFORMATION
The CVA3404T is a high voltage triple CRT driver suitiable to
drive 69kHz, 1280 x 1024 CRT displays. It features a high
impedance input to match any pre-amplifier. The CVA3404T
has a true class AB output stage that results in excellent gray
scale linearity and consistent EMI performance.
As with any high speed amplifier used in CRT display
applications, specific precaution should be taken to get the
required performance. Power supply should be by pass as
close to the device pin as possible. Use 0.01
f very near to
the device and a large capacitor of 10
f or more (preferable
100
f) near the device. A 0.1
f and 10
f should be connected
near the V
bias
pin (#10). Arc protection is very essential. Fast
diodes together with the spark gap will achieve sufficient
protection. However, in certain applications depends on the
tubes a high value of resistor is required to reduce the current
into the CVA3404T during arcing. This will result in less than
desireable performance some of which can be restored by
using a peaking inductor at the output pin,
Figure 2. Another
way to achieve this is by using a RC network at the output of
the device and use a peaking inductor at the tube,
Figure 3.
The rise and fall time of the CVA3404T may suffer due to
stray capacitances associated with the PC Board and other
components. It can be improved by carefully designing the
PC Board where the output stage and input stage ground path
are seperated. Calogic will assist customers in the layout of
the PC Board that will result in quick EMI passage and better
performance. The output peaking should be used only to
restore the performance loss due to stray capacitances. Over
peaking will cause excessive ringing that will have better
results but poor EMI. The DC restore circuit is also important
when considering the high frequency performance. Using
CVA4501, DC Bias IC, better results can be obtained and
high frequency performance can be maximixed.
THERMAL CONSIDERATIONS
Power supply current increases as the input signal increases
and consequently power dissipation also increases.
The CVA3404T cannot be used without heat sinking.
Figure 4
shows the power dissipated in each channel over the
operating voltage range of the device. Under white screen
conditions, i.e.: 25V output, dissipation increases to 9.5W
total. The CVA3405T case temperature must be maintained
below +100
o
C. If the maximum expected ambient
temperature is +50
o
C, then a heat sink is needed with thermal
resistance equal to or less than:
R
th
=
(
100
-
50
o
C
)
9.5W
=
5.3
o
C/W
The CVA3404T maximum load is 600
to ground or V
+
.
The output of CVA3404T is not short circuit proof. Any resistance
to V
+
or Ground should be > 600
.
FIGURE 2.
1P-31
V
BIAS
VIDEO
CVA3404T
+80V
L
R
91
SPARK
GAP
33
FIGURE 3.
1P-32
V
BIAS
VIDEO
CVA3404T
+80V
1K
SPARK
GAP
33
C
CVA4501
BIAS
DC BIAS
I.C.
Vcc
L
R
CVA3404T
CORPORATION
FIGURE 4. APPLICATION CIRCUIT
1P-33
GND
TAB
V
BIAS
C1 = 0.01
F
C2 = 100
F
C3 = 0.1
F
C4 = 100
F
C5 = 2.2
F
C6 = 27pf
C7 = 40 - 120pf
D1, D2 = FHD400
L = 150 - 33nH
R1 = 820
R2 = 22
R3 = 47(1/2W)
R4 = 47
R2
R3
C4
C3
C2
C1
D2
D1
V 6
CC
10
1,3,5
V
OUT
C5
CVA3404T
R1
L
V
IN
VIDEO
INPUT
11,9,8
DC BIAS
SPARK
GAP
C6
R4
2,4,7
16
14
12
10
8
6
4
2
0
1P-19
POWER DISSIPATION vs V
PO
W
E
R (W)
(V)
V
CC
55
60
65
70
75
80
85
= 25V
V
OUT
= V = 10V
V
OUT
CC
CC
V vs V
OUT
IN
(V
)
V
OUT
80
70
60
50
40
30
20
10
0
1P-18
(V)
V
IN
0
1
2
3
4
5
6
7
1P-29
PULSE RESPONSE
VOLTS (
V
)
1
0
V/
DIV.
TIME = 20ns/DIV.
1P-20
BANDWIDTH
5 dB
/ DI
V
.
1MHz
10MHz
100MHz
0
5
10
15
20
25
30
TYPICAL CHARACTERISTICS
Information furnished by Calogic is believed to be accurate and reliable. However, no responsibility is assumed for its use: nor for any infringement of patents or other
rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent rights of Calogic.
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
PDF 
ZIP